Three residents were rescued by Boston firefighters using ladders. One occupant of the building jumped from an upper story, according to firefighters.

"One person had jumped. Another person was hanging from the window," said Deputy Chief Stephen Dunbar.

Authorities said the student, a woman, died after becoming trapped in the attic. Firefighters were unable to reach her.

"It appears they were trying to get through the dormer window immediately, and they fell backwards, and that's where we found her," Dunbar said.

The victim’s identity has not been released. Two other Boston University students were among those injured, according to the school.

Boston Fire Department Spokesman Steve MacDonald said in attempts to get to the victim, one firefighter fell through a second-story floor and another fell down some stairs.

"During the fire, we had one firefighter go through the floor, from the second floor to the first floor,” MacDonald said. "He was able to walk out on his own power.”

MacDonald said 18 people had been living in the house.

BU Today reported that 9 of those residents were Boston University students.

"We have since come to find out that 18 people lived in this home, from the basement through to the attic. We have called Inspectional Services to the scene to determine the legality of all that," MacDonald said.

The injuries to the other nine residents and six firefighters were said to be not life-threatening.

The cause of the fire is under investigation.

Photos: Fire kills 1, injures 15

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Boston Fire Dept.

One woman was killed, and nine other residents and six Boston firefighters were injured in a fire in Allston Sunday morning.

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